1. Field of the Invention
The invention relates to a lock assembly with a curved keyway, more particularly to a lock assembly having a lock body with a longitudinal curved keyway and at least two differently oriented sets of tumbler members provided thereon.
2. Description of the Related Art
Co-pending U.S. patent application Ser. No. 07/520,579 discloses a lock assembly having a lock body with a curved keyway and a flexible key. The curved keyway removes tumbler members provided on the lock body from straight access which makes actuation or manipulation of the tumbler members more difficult for a thief. The flexible key has a plurality of knuckles hinged to one another. The knuckles provide a degree of stiffness sufficient to permit insertion of the flexible key into the curved keyway. When inserted, the knuckles actuate the tumbler members and are capable of transmitting the torque applied so as to rotate the lock body and unlock the lock assembly.
Some of the drawbacks of the above-mentioned lock assembly are as follows: 1. Shaking experienced by the flexible key can cause untimely disengagement and eventual accidental misplacement of the key from the lock body. Referring to FIG. 1, the lock body 1 with curved keyway 12 is installed in a car ignition device. The flexible key 11 is inserted into the keyway 12 and friction between the tumbler members and the key 11 hampers unforced disengagement of the flexible key 11 from the lock body 1. However, untimely release of the key 11 from the lock body 1 is still possible because of the weight of the handle portion 13 of the key 11 and because of the vibrations normally experienced by a car when in motion. 2. The curved keyway 12 prevents straight access of the tumbler members to correspondingly increase the difficulty in the actuation or manipulation of the tumbler members for a thief. However, the rectangular cross-section of the keyway 12 permits installation of the tumbler members in only a single direction.